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Experimental research on the launching system of auxiliary charge with filter cartridge structure

Defence Technology（防务技术） 2024年第1期31卷 41-48页

作者： Zi-Jun Chen Ze He Hong-Hao Ma Lu-Qing wang Zhao-Wu Shen CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui230027PR China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefeiAnhui230026PR China

A launching system with a filter cartridge structure was proposed to improve the muzzle velocity of the *** combustion chamber of the launching system is divided into two fixed chambers,one is located in the breech chamber,and the other is arranged in the *** breech chamber charge was ignited first,and the charges in the auxiliary chambers were ignited by the high-temperature,highpressure combustible gas trailing the *** this way,the combustible gas in the auxiliary chambers could compensate for the pressure drop caused by the movement of the *** proposed device features the advantage of launching a projectile with high muzzle velocity without exceeding the maximum pressure in the *** order to obtain some internal ballistic characteristics of the launch system,some critical structure,such as the length of the filter cartridge auxiliary charge,the combustion degree of the propellant in the chamber,and the length of the barrel,are *** experimental results show that with the increased auxiliary charge length,a pressure plateau or even a secondary peak pressure can be formed,which is less than the peak *** projectile velocity increased by 23.57%,14.64%,and 7.65%when the diaphragm thickness was 0 mm,1 mm,and2 mm,*** muzzle velocity of the projectile can be increased by 13.42%by increasing the length of the *** the same charge condition,with the increase of barrel length,the energy utilization rate of propellant increases by 28.64%.

关键词： Interior ballistics Charge structures Launch system Charge design

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Numerically investigation of particle distribution in industrial-scale DTB crystallizer based on CFD

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Particuology 2024年第10期93卷 186-202页

作者： Jinju Ma Weiyu wang Wei Huang Wei Liu Xinding Yao Tao Li Baozeng Ren School of Environment Engineering Yellow River Conservancy Technical InstituteKaifeng475004China School of Chemical Engineering Zhengzhou UniversityZhengzhou450001China School of Chemistry and Chemical Engineering Wuhan University of Science and TechnologyWuhan430081China Kaifeng Engineering Research Center for Municipal Wastewater Treatment Kaifeng475004China Henan Engineering Technology Research Center of Green Coating Materials 475004KaifengChina

The suspension state of crystals in the crystallizer is one of the important indicators for evaluating the adaptability of the *** study adopted the Euler-Eulerian two-fluid model to simulate and analyze the fluid motion of solid-liquid two-phase flow in the industrial-grade DTB crystallization kettle,as well as the phase suspension distribution of crystal *** main influencing factors investigated are:the heat transfer effect,the height of the bottom of the crystallizer,the number and position of the stirring paddle,crystal size and crystal volume *** on the research of Euler-Eulerian method to simulate fluids,the Euler-Lagrangian method was further used to simulate the motion state of particle phases with different particle sizes in the *** was found that the designed DTB crystallizer has good recycle mixing *** particles can be mixed evenly during the operation,which can fully realize the solid-liquid mixing and suspension effect of the drug under study.

关键词： Draff tube baffle(DTB)crystallizer Two-fluid model Numerical simulation Turbulence modelling

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Ionic liquid-trimetallic electrocatalytic system for C–O bond cleavage in lignin model compounds and lignin under ambient conditions

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Nano Research 2024年第4期17卷 2420-2428页

作者： Guangyong Liu Yumiao Lu JunFeng Lu Yanlei wang Shijing Liang Hongyan He Lilong Jiang National Engineering Research Center of Chemical Fertilizer Catalyst Fuzhou UniversityFuzhou 350002China CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Multiphase Complex SystemsBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial TechnologyZhengzhou 450000China

Electrocatalytic depolymerization of lignin into value-added chemicals offers a promising technique to make biorefining ***,we report a robust trimetallic PdNiBi electrocatalyst for reductive C–O bond cleavage of different lignin model dimers and oxidized lignin under mild *** reduction reaction proceeds with complete substrate conversion and excellent yields toward monomers of phenols(80%–99%)and acetophenones(75%–96%)in the presence of an ionic liquid electrolyte with operational *** experimental investigations together with density functional theory(DFT)calculations reveal that the outstanding performance of the catalyst results from the synergistic effect of the metal elements,which facilitates the easier formation of a key Cαradical intermediate and the facile desorption of the as-formed products at the *** results open up new opportunities for lignin valorization through the green electrocatalytic approach.

关键词： electrocatalytic depolymerization lignin Ionic liquids density functional theory(DFT)calculation

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A highly reliable encoding and decoding communication framework based on semantic information

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Digital Communications and Networks 2024年第3期10卷 509-518页

作者： Yichi Zhang Haitao Zhao Kuo Cao Li Zhou Zhe wang Yueling Liu Jibo Wei College of Electronic Science and Technology National University of Defense TechnologyChangsha 410073China

Increasing research has focused on semantic communication,the goal of which is to convey accurately the meaning instead of transmitting symbols from the sender to the *** this paper,we design a novel encoding and decoding semantic communication framework,which adopts the semantic information and the contextual correlations between items to optimize the performance of a communication system over various *** the sender side,the average semantic loss caused by the wrong detection is defined,and a semantic source encoding strategy is developed to minimize the average semantic *** further improve communication reliability,a decoding strategy that utilizes the semantic and the context information to recover messages is proposed in the *** simulation results validate the superior performance of our strategies over state-of-the-art semantic coding and decoding policies on different communication channels.

关键词： Semantic information Semantic encoding method Context-based decoding method

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Prevalence of hypertension and its associations with body composition across Chinese and American children and adolescents

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World Journal of Pediatrics 2024年第4期20卷 392-403页

作者： Li-wang Gao Yi-Wen Huang Hong Cheng Xi wang Hong-Bo Dong Pei Xiao Yin-Kun Yan Xin-Ying Shan Xiao-Yuan Zhao Jie Mi Center for Non-Communicable Disease Management Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthNo.56 Nanlishi RoadXicheng DistrictBeijing100045China Department of Epidemiology Capital Institute of PediatricsNo.2 Yabao RoadChaoyang DistrictBeijing100020China Key Laboratory of Major Diseases in Children Ministry of EducationBeijingChina

Background The age of onset of hypertension(HTN)is decreasing,and obesity is a significant risk *** prevalence and racial disparities in pediatric HTN and the association between body composition and blood pressure are insufficiently *** study aimed to evaluate the prevalence of HTN in Chinese and American children and adolescents and to assess the relationship between various body composition indices and *** Seven thousand,five hundred and seventy-three Chinese and 6239 American children and adolescents aged 8–18 years from the 2013–2015 China Child and Adolescent Cardiovascular Health study and the 2011–2018 National Health and Nutrition Examination Surveys were *** pressure and body composition(fat and muscle)were measured by trained *** crude prevalence and age-standardized prevalence rate(ASPR)of primary HTN and its subtypes[isolated systolic hypertension(ISH)and isolated diastolic hypertension(IDH)]were calculated based on 2017 American Academy of Pediatrics ***-adjusted linear regression coefficients and odds ratios(ORs)were calculated to assess the associations of body composition indicators with HTN,ISH and *** The ASPR of HTN was 18.5%in China(CN)and 4.6%in the United States(US),whereas the obesity prevalence was 7.4%and 18.6%,and the population attributable risk of HTN caused by overweight and obesity was higher in the US than in *** fat mass,muscle mass and body fat percentage mass were associated with a higher risk of HTN in both *** percent of muscle body mass had a protective effect on HTN and ISH in both countries[HTN(CN:OR=0.83,95%CI=0.78–0.88;US:OR=0.72,95%CI=0.64–0.81);ISH(CN:OR=0.87,95%CI=0.80–0.94;US:OR=0.71,95%CI=0.62–0.81)],and the protective effect was more common among children and adolescents with high levels of physical *** The burden of HTN in Chinese children and adolescents was substantial and much greater than that in the US,and th

关键词： Body composition Children and adolescents China Child and Adolescent Cardiovascular Health Hypertension National Health and Nutrition Examination Surveys

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Trajectory compensation for multi-robot coordinated lifting system considering elastic catenary of the rope

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High Technology Letters 2024年第3期30卷 252-262页

作者： ZHAO Xiangtang ZHAO Zhigang SU Cheng MENG Jiadong wang Baoxi School of Mechanical Engineering Lanzhou Jiaotong UniversityLanzhou 730070P.R.China

The multi-robot coordinated lifting system is an unconstrained system with a rigid and flexible *** deformation of the flexible rope causes errors in the movement trajectory of the lifting *** on the kinematic and dynamic analysis of the lifting system,the elastic catenary mod-el considering the elasticity and mass of the flexible rope is established,and the effect of the deform-ation of the flexible rope on the position and posture of the suspended object is *** to the deformation of flexible rope,a real-time trajectory compensation method is proposed based on the compensation principle of position and *** the lifting task of the low-speed move-ment,this is compared with that of the system which neglects the deformation of the flexible *** trajectoy of the lifting system considering the deformation of flexible *** results show that the mass and elasticity of the flexible rope can not be ***,the proposed trajectory compensation method can improve the movement accuracy of the lifting system,which verifies the ef-fectiveness of this compensation *** research results provide the basis for trajectory plan-ning and coordinated control of the lifting system。

关键词： multi-robot lifting system deformation of flexible rope elastic catenary model compensation principle of position and posture trajectory compensation

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Joint Optimization of Energy Consumption and Network Latency in Blockchain-Enabled Fog Computing Networks

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China Communications 2024年第4期21卷 104-119页

作者： Huang Xiaoge Yin Hongbo Cao Bin wang Yongsheng Chen Qianbin Zhang Jie School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China School of Communication and Information Engineering University of SheffieldUnited Kingdom

Fog computing is considered as a solution to accommodate the emergence of booming requirements from a large variety of resource-limited Internet of Things(IoT)*** ensure the security of private data,in this paper,we introduce a blockchain-enabled three-layer device-fog-cloud heterogeneous network.A reputation model is proposed to update the credibility of the fog nodes(FN),which is used to select blockchain nodes(BN)from FNs to participate in the consensus *** to the Rivest-Shamir-Adleman(RSA)encryption algorithm applied to the blockchain system,FNs could verify the identity of the node through its public key to avoid malicious ***,to reduce the computation complexity of the consensus algorithms and the network overhead,we propose a dynamic offloading and resource allocation(DORA)algorithm and a reputation-based democratic byzantine fault tolerant(R-DBFT)algorithm to optimize the offloading decisions and decrease the number of BNs in the consensus algorithm while ensuring the network *** results demonstrate that the proposed algorithm could efficiently reduce the network overhead,and obtain a considerable performance improvement compared to the related algorithms in the previous literature.

关键词： blockchain energy consumption fog computing network Internet of Things latency

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Nano-silica modified lightweight and high-toughness carbon fiber/phenolic ablator with excellent thermal insulation and ablation performance

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Defence Technology（防务技术） 2024年第1期31卷 192-199页

作者： Wenjie Xu Wenda Song Xianfeng Jia Cheng Ma Jitong wang Wenming Qiao Licheng Ling State Key Laboratory of Chemical Engineering East China University of Science and TechnologyShanghai 200237China School of Chemical Engineering and Materials Changzhou Institute of TechnologyChangzhou 213032China Key Laboratory of Specially Functional Polymeric Materials and Related Technology(Ministry of Education) School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

Lightweight and high-toughness carbon fiber/phenolic ablator(CFPA)is required as the Thermal Protection System(TPS)material of aerospace vehicles for next-generation space *** improve the ablative properties,silica sol with good particle size distribution prepared using tetramethoxysilane(TMOS)was blended with natural rubber latex and deposited onto carbon fiber felt,which was then integrated with phenolic aerogel matrix,introducing nano-silica into the framework of *** modified CFPA with a low density of 0.28—0.31 g/cm3exhibits strain-in-fracture as high as 31.2%and thermal conductivity as low as 0.054 W/(m·K).Furthermore,a trace amount of nano-silica could effectively protect CFPA from erosion of oxidizing atmosphere in different high-temperature *** oxyacetylene ablation test of 3000°C for 20 s shows a mass ablation rate of 0.0225 g/s,a linear ablation rate of 0.209 mm/s for the modified CFPA,which are 9.64%and 24.82%lower than the unmodified ***,the long-time butane ablation test of 1200°C for 200 s shows an insignificant recession with mass and linear ablation rate of 0.079 g/s and 0.039 mm/s,16.84%and 13.33%lower than the unmodified ***,the fixed thermocouple in the test also demonstrates a good thermal insulation performance with a low peak back-face temperature of 207.7°C,12.25%lower than the unmodified ***,the nano-silica modified CFPA with excellent overall performance presents promising prospects in high-temperature aerospace applications.

关键词： Nano-silica Carbonfiber Phenolic aerogel Insulation Ablation

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Life cycle assessment of homogeneous Fenton process as pretreatment for refractory pharmaceutical wastewater

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Frontiers of Chemical Science and Engineering 2024年第5期18卷 1-11页

作者： Maojun Zou Jie Wei Yuanyuan Qian Yanjing Xu Zhihuang Fang Xuejing Yang Zhiyuan wang School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Engineering Laboratory of Lean Operational Technologies for Full Water System East China University of Science and TechnologyShanghai 200237China Mcwong Environmental Technology Company Limited Shanghai 200135China National Engineering Laboratory of High Concentration and Refractory Organic Wastewater Treatment Technology East China University of Science and TechnologyShanghai 200237China

The applicability of the life cycle assessment(LCA)to the Fenton process should be considered not only at the laboratory-scale but also at the *** this study,the LCA process was applied to evaluate the homo-geneous Fenton process for the treatment of high salinity pharmaceutical *** potential environmental impacts were calculated using Simapro software implemen-ting the CML 2001 methodology with normalization factors of 1995 *** data obtained directly from the full-scale wastewater treatment plant and labora-tory were used to conduct a life cycle inventory analysis,ensuring highly accurate *** normalized results,the Fenton process reveals sensitive indicators,primarily toxi-city indicators(human toxicity,freshwater aquatic toxicity,and marine aquatic toxicity),as well as acidification and eutrophication impacts,contributed by hydrogen peroxide and iron sludge incineration,***,hydrogen peroxide and iron sludge incineration contribute significantly,accounting for at least 78%of these *** sludge treatment phase,treatment of iron mud and infrastructure of hazardous waste incineration plants were the key contributors of environmental impacts,adding up to more than 95%.This study suggests the need to develop efficient oxidation processes and effective iron sludge treatment methods to reduce resource utilization and improve environmental benefits.

关键词： advanced oxidation processes full-scale life cycle assessment Fenton process pharmaceutical high-salinity wastewater

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Self-cleaning effect and secondary swirling clean gas for suppressing particle deposition on vortex finder of gas cyclones

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Particuology 2024年第7期90卷 72-87页

作者： Zhanpeng Sun Huandi Yang Kaixuan Zhang Zhiyuan wang Zhenyuan Hong Guang Yang School of Mechanical Engineering Hebei University of Science&TechnologyShijiazhuang050018China

In order to suppressing the particle deposition on vortex finder,a series of gas cyclones with the secondary swirling clean gas were developed inspired by the gas purge *** of the width and extension length of the flow channel as well as the secondary inlet velocity and running time on the particle deposition pattern,the deposited particle mass and the cyclones'performance were experimentally investigated,*** results show that the ultrafine particles(Stokes number Stk<0.0358)are mainly loose deposited on the walls under the secondary *** to the conventional cyclone with single tangential inlet,the total deposited particle mass of the improved cyclone has a maximum reduction more than 60%,and the collecting efficiency is increased up to 97.5%under the basically same pressure *** corresponding no-deposition area is increased by about 13%,and remains constant in spite of extending the running ***,an interesting phenomenon named"self-cleaning effect"of the vortex finder was captured for the gas cyclones,and mechanism of the secondary clean gas on the particle deposition is preliminarily *** results can deepen the understanding of the particle deposition on the vortex finder and guide the design of the anti-coking gas cyclones.

关键词： Cyclones Vortex finder Particle deposition Gas purge effect Self-cleaning effect

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